Whatsapp AI Agente - Prompt error

Soho · March 13, 2025, 1:00am

I tried to create a workflow in which I have a message being received on WhatsApp and I use openai to answer writing a message back. The problem is that I get a message about a prompt missing, even though I had already written it.

ThinkBot · March 13, 2025, 1:01am

Could you ctl a, ctl c (or cmd) to copy your workflow and then on the forums click ‘</>’ and paste that into the backticks?

Can you show what the error is?

solomon · March 13, 2025, 1:27pm

Hey @Soho

Another Brazilian here

The problem is the USER prompt. See this error icon here?

Set it up like this:

Remember to enable the Expression tab here:

You can copy and paste this node to your workspace to see how it’s done:

Take a look at this template for more detailed instructions.

.

If my reply answers your question, please remember to mark it as a solution.

ThinkBot · March 13, 2025, 5:28pm

Ah yes, I missed that. @solomon is correct. A system prompt defines how the agent functions, and the Prompt (User Message) is the “question” or “query” you ask the agent itself.

Soho · March 14, 2025, 4:20am

Thx for the help, but solved it. Now my workflow is much more complex, I am developing it quite fast, N8N is quite amazing…

Soho · March 14, 2025, 4:22am

Hey Solomon! Yes… another brazilian . I managed to solve the problem, now my problems are a bit more complex, posting soon for more help. N8N, what a tool, right? Loving it… Thx anyway!!!

But I still have a question though, is whatsapp more complicated to deal with? It seems to lose connection all the time, as the credential suddenly expires all the time

ThinkBot · March 14, 2025, 4:36am

You may now be encountering different errors. There are a couple known bugs with WhatsApp at the moment that are under investigation, you can find/search them on the n8n github:

github.com/n8n-io/n8n

WhatsApp Nodes with problems since version 1.82.0

opened 11:50PM - 10 Mar 25 UTC

aquesada-tecnova

in linear

## Describe the problem/error/question All the WhatsApp nodes are failing since …I updated to 1.82.0 (tried 1.82.1 too and got the same result). I downgraded to 1.81.4 and started working again without problems. ## What is the error message (if any)? I don't get an explicit error, only an error symbol on WhatsApp nodes, but I don't get an explicit error message. ## Please share your workflow/screenshots/recording <img width="2982" alt="Image" src="https://github.com/user-attachments/assets/967891ff-91a0-4294-a457-0781836a9c11" /> (Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.) ⚠️ WARNING ⚠️ If you have sensitive data in your workflow (like API keys), please remove it before sharing. ``` { "nodes": [ { "parameters": { "workflowInputs": { "values": [ { "name": "message", "type": "object" } ] } }, "type": "n8n-nodes-base.executeWorkflowTrigger", "typeVersion": 1.1, "position": [ -1220, -220 ], "id": "b62af59d-b4f7-454c-8055-635c22b3a0a7", "name": "When Executed by Another Workflow" }, { "parameters": { "rules": { "values": [ { "conditions": { "options": { "caseSensitive": true, "leftValue": "", "typeValidation": "strict", "version": 2 }, "conditions": [ { "leftValue": "={{ $json.message.type }}", "rightValue": "text", "operator": { "type": "string", "operation": "equals" } } ], "combinator": "and" }, "renameOutput": true, "outputKey": "texto" }, { "conditions": { "options": { "caseSensitive": true, "leftValue": "", "typeValidation": "strict", "version": 2 }, "conditions": [ { "id": "ac875247-6d9e-4576-9434-edfd1a168e88", "leftValue": "={{ $json.message.type }}", "rightValue": "audio", "operator": { "type": "string", "operation": "equals", "name": "filter.operator.equals" } } ], "combinator": "and" }, "renameOutput": true, "outputKey": "audio" }, { "conditions": { "options": { "caseSensitive": true, "leftValue": "", "typeValidation": "strict", "version": 2 }, "conditions": [ { "id": "052b69fe-a7b4-4fcf-93ed-05e24fa3016e", "leftValue": "={{ $json.message.type }}", "rightValue": "image", "operator": { "type": "string", "operation": "equals", "name": "filter.operator.equals" } } ], "combinator": "and" }, "renameOutput": true, "outputKey": "image" }, { "conditions": { "options": { "caseSensitive": true, "leftValue": "", "typeValidation": "strict", "version": 2 }, "conditions": [ { "id": "e58229dd-cdd1-4769-a250-caa2116557e0", "leftValue": "={{ $json.message.type }}", "rightValue": "video", "operator": { "type": "string", "operation": "equals", "name": "filter.operator.equals" } } ], "combinator": "and" }, "renameOutput": true, "outputKey": "video" }, { "conditions": { "options": { "caseSensitive": true, "leftValue": "", "typeValidation": "strict", "version": 2 }, "conditions": [ { "id": "42099920-c627-41dc-8279-95fcc686fb29", "leftValue": "={{ $json.message.type }}", "rightValue": "=document", "operator": { "type": "string", "operation": "equals", "name": "filter.operator.equals" } } ], "combinator": "and" }, "renameOutput": true, "outputKey": "document" } ] }, "options": { "fallbackOutput": "extra" } }, "type": "n8n-nodes-base.switch", "typeVersion": 3.2, "position": [ -1020, -280 ], "id": "052c810a-8211-4b8d-ad34-1732c63f6ace", "name": "Switch" }, { "parameters": { "workflowId": { "__rl": true, "value": "V9DXTczzKzVpF4Ka", "mode": "list", "cachedResultName": "Enviar WhatsApp Tecnova SalesMate" }, "workflowInputs": { "mappingMode": "defineBelow", "value": { "telefono": "={{ $('When Executed by Another Workflow').item.json.message.from }}", "tipo": "=text", "texto": "Tipo de mensaje no soportado" }, "matchingColumns": [], "schema": [ { "id": "texto", "displayName": "texto", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" }, { "id": "telefono", "displayName": "telefono", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" }, { "id": "tipo", "displayName": "tipo", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" } ], "attemptToConvertTypes": false, "convertFieldsToString": true }, "options": {} }, "type": "n8n-nodes-base.executeWorkflow", "typeVersion": 1.2, "position": [ -1140, 460 ], "id": "8544dd4c-b7da-4336-8f97-aa51b9b28f64", "name": "Enviar WhatsApp Tipo No Soportado" }, { "parameters": { "modelName": "models/gemini-2.0-flash-001", "options": {} }, "type": "@n8n/n8n-nodes-langchain.lmChatGoogleGemini", "typeVersion": 1, "position": [ 160, -160 ], "id": "2bfd765b-d277-4900-a191-8b1990e30c1b", "name": "Google Gemini Chat Model", "credentials": { "googlePalmApi": { "id": "S193yQpV9cWxi0U8", "name": "Google Gemini Pagado" } } }, { "parameters": { "jsonSchemaExample": "{\n\t\"Tipo_Solicitud\": \"Estado_de_Cuenta|Cotizacion|Precio|Stock\",\n\t\"Solicitud\": {\n\"Codigo_Cliente\": \"Codigo\",\n\"Nombre_Cliente\": \"Nombre\",\n\"Productos\": [\n { \"Codigo_Producto\":\"Codigo\",\n\"Cantidad\": \"Cantidad\",\n\"Descripcion\": \"Descripcion\"\n }\n]\n}\n}" }, "type": "@n8n/n8n-nodes-langchain.outputParserStructured", "typeVersion": 1.2, "position": [ 300, -180 ], "id": "4876f244-25cb-4a24-970f-61992b736e3e", "name": "Structured Output Parser" }, { "parameters": { "resource": "media", "operation": "mediaUrlGet", "mediaGetId": "={{ $('When Executed by Another Workflow').item.json.message.audio.id }}" }, "type": "n8n-nodes-base.whatsApp", "typeVersion": 1, "position": [ -620, 20 ], "id": "51ed78f7-6c92-4c9c-8aec-e351b5b1fdb6", "name": "Get audio URL", "webhookId": "0245b673-4e91-4465-99bd-ddcecbbc06c2", "credentials": { "whatsAppApi": { "id": "kwhCAjIH3S8LICMA", "name": "WhatsApp SalesMate 7177-7465" } } }, { "parameters": { "url": "={{ $json.url }}", "authentication": "predefinedCredentialType", "nodeCredentialType": "whatsAppApi", "options": {} }, "id": "9c79153d-dc9e-4c40-a0d4-c486e57a615b", "name": "Download Audio1", "type": "n8n-nodes-base.httpRequest", "position": [ -460, 20 ], "typeVersion": 4.2, "credentials": { "whatsAppApi": { "id": "kwhCAjIH3S8LICMA", "name": "WhatsApp SalesMate 7177-7465" } } }, { "parameters": { "method": "POST", "url": "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-001:generateContent", "authentication": "predefinedCredentialType", "nodeCredentialType": "googlePalmApi", "sendHeaders": true, "headerParameters": { "parameters": [ { "name": "Content-Type", "value": "application/json" } ] }, "sendBody": true, "specifyBody": "json", "jsonBody": "={{\n{\n \"contents\": [{\n \"parts\":[\n {\"text\": \"Only Transcribe this audio. Don't add any more information\"},\n {\"inlineData\": {\n \"mimeType\": `audio/${$binary.data.fileExtension}`,\n \"data\": $input.item.binary.data.data }\n }\n ]\n }]\n}\n}}", "options": {} }, "id": "1727733c-c37b-431f-b089-8442f389057c", "name": "Google Gemini Audio1", "type": "n8n-nodes-base.httpRequest", "position": [ -240, 20 ], "typeVersion": 4.2, "credentials": { "googlePalmApi": { "id": "S193yQpV9cWxi0U8", "name": "Google Gemini Pagado" } } }, { "parameters": { "assignments": { "assignments": [ { "id": "2ec0e573-373b-4692-bfae-86b6d3b9aa9a", "name": "text", "type": "string", "value": "={{ $json.candidates[0].content.parts[0].text }}" } ] }, "options": {} }, "id": "c6f79fe7-9541-432a-8072-6aa584336373", "name": "Format Audio", "type": "n8n-nodes-base.set", "position": [ -40, 20 ], "typeVersion": 3.4 }, { "parameters": { "resource": "media", "operation": "mediaUrlGet", "mediaGetId": "={{ $('When Executed by Another Workflow').item.json.message.image.id }}" }, "id": "55a02bf5-a04f-4b8a-a4fe-edffc723deb9", "name": "Get Image URL1", "type": "n8n-nodes-base.whatsApp", "position": [ -620, 300 ], "typeVersion": 1, "webhookId": "9f4c6e59-54d5-44ca-8546-2986d313988e", "credentials": { "whatsAppApi": { "id": "kwhCAjIH3S8LICMA", "name": "WhatsApp SalesMate 7177-7465" } } }, { "parameters": { "url": "={{ $json.url }}", "authentication": "predefinedCredentialType", "nodeCredentialType": "whatsAppApi", "options": {} }, "id": "342811b3-f010-40eb-971e-82663272b3c5", "name": "Download Image", "type": "n8n-nodes-base.httpRequest", "position": [ -400, 300 ], "typeVersion": 4.2, "credentials": { "whatsAppApi": { "id": "kwhCAjIH3S8LICMA", "name": "WhatsApp SalesMate 7177-7465" } } }, { "parameters": { "promptType": "define", "text": "={{ $('When Executed by Another Workflow').item.json.message.image.caption || 'Esta es una imagen enviada por el usuario. Descríbela y transcribe todo el texto que esté en ella.' }}", "messages": { "messageValues": [ { "type": "HumanMessagePromptTemplate", "messageType": "imageBinary" } ] } }, "id": "cac50f2a-b6d4-496b-8f65-dd121b0c3478", "name": "Image Explainer", "type": "@n8n/n8n-nodes-langchain.chainLlm", "position": [ -180, 460 ], "typeVersion": 1.4 }, { "parameters": { "resource": "media", "operation": "mediaUrlGet", "mediaGetId": "={{ $('When Executed by Another Workflow').item.json.message.video.id }}" }, "id": "59d44f1c-c970-4b8d-8410-0b2ee2a7fee1", "name": "Get Video URL1", "type": "n8n-nodes-base.whatsApp", "position": [ -580, 860 ], "typeVersion": 1, "webhookId": "a94d46c2-3b90-443e-8b56-b5243b5a9025", "credentials": { "whatsAppApi": { "id": "kwhCAjIH3S8LICMA", "name": "WhatsApp SalesMate 7177-7465" } } }, { "parameters": { "url": "={{ $json.url }}", "authentication": "predefinedCredentialType", "nodeCredentialType": "whatsAppApi", "options": {} }, "id": "efaff558-964d-4134-861e-5d5ea9cdaa9c", "name": "Download Video1", "type": "n8n-nodes-base.httpRequest", "position": [ -360, 1000 ], "typeVersion": 4.2, "credentials": { "whatsAppApi": { "id": "kwhCAjIH3S8LICMA", "name": "WhatsApp SalesMate 7177-7465" } } }, { "parameters": { "workflowId": { "__rl": true, "value": "V9DXTczzKzVpF4Ka", "mode": "list", "cachedResultName": "Enviar WhatsApp Tecnova SalesMate" }, "workflowInputs": { "mappingMode": "defineBelow", "value": { "telefono": "={{ $('When Executed by Another Workflow').item.json.message.from }}", "tipo": "text", "texto": "={{ $json.candidates[0].content.parts[0].text }}" }, "matchingColumns": [], "schema": [ { "id": "texto", "displayName": "texto", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" }, { "id": "telefono", "displayName": "telefono", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" }, { "id": "tipo", "displayName": "tipo", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" } ], "attemptToConvertTypes": false, "convertFieldsToString": true }, "options": {} }, "type": "n8n-nodes-base.executeWorkflow", "typeVersion": 1.2, "position": [ 180, 1020 ], "id": "6225ab27-8d3a-446d-b24f-0d15a29f1c17", "name": "Enviar WhatsApp Respuesta Video con Caption" }, { "parameters": { "method": "POST", "url": "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-001:generateContent", "authentication": "predefinedCredentialType", "nodeCredentialType": "googlePalmApi", "sendHeaders": true, "headerParameters": { "parameters": [ { "name": "Content-Type", "value": "application/json" } ] }, "sendBody": true, "specifyBody": "json", "jsonBody": "={{\n{\n \"contents\": [{\n \"parts\":[\n {\"text\": $('When Executed by Another Workflow').item.json.message.video.caption || 'Describe detalladamente este video en español.' },\n {\"inlineData\": {\n \"mimeType\": `video/${$binary.data.fileExtension}`,\n \"data\": $input.item.binary.data.data }\n }\n ]\n }]\n}\n}}", "options": {} }, "id": "a3235414-1f0b-44b3-87cc-5530f275dc5a", "name": "Google Gemini Video", "type": "n8n-nodes-base.httpRequest", "position": [ -120, 1000 ], "typeVersion": 4.2, "credentials": { "googlePalmApi": { "id": "S193yQpV9cWxi0U8", "name": "Google Gemini Pagado" } } }, { "parameters": { "workflowId": { "__rl": true, "value": "V9DXTczzKzVpF4Ka", "mode": "list", "cachedResultName": "Enviar WhatsApp Tecnova SalesMate" }, "workflowInputs": { "mappingMode": "defineBelow", "value": { "telefono": "={{ $('When Executed by Another Workflow').item.json.message.from }}", "tipo": "text", "texto": "={{ $('Image Explainer').item.json.text }}" }, "matchingColumns": [], "schema": [ { "id": "texto", "displayName": "texto", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" }, { "id": "telefono", "displayName": "telefono", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" }, { "id": "tipo", "displayName": "tipo", "required": false, "defaultMatch": false, "display": true, "canBeUsedToMatch": true, "type": "string" } ], "attemptToConvertTypes": false, "convertFieldsToString": true }, "options": {} }, "type": "n8n-nodes-base.executeWorkflow", "typeVersion": 1.2, "position": [ 180, 460 ], "id": "b789989c-39ff-4320-8a31-25deb8ef1a96", "name": "Enviar WhatsApp Respuesta Texto1" }, { "parameters": { "modelName": "models/gemini-2.0-flash-001", "options": {} }, "type": "@n8n/n8n-nodes-langchain.lmChatGoogleGemini", "typeVersion": 1, "position": [ -160, 660 ], "id": "570e8ac9-9aa5-4112-9d4f-edf845fb0dd2", "name": "Google Gemini Image Model", "credentials": { "googlePalmApi": { "id": "S193yQpV9cWxi0U8", "name": "Google Gemini Pagado" } } } ], "connections": { "When Executed by Another Workflow": { "main": [ [ { "node": "Switch", "type": "main", "index": 0 } ] ] }, "Switch": { "main": [ [], [ { "node": "Get audio URL", "type": "main", "index": 0 } ], [ { "node": "Get Image URL1", "type": "main", "index": 0 } ], [ { "node": "Get Video URL1", "type": "main", "index": 0 } ], [ { "node": "Enviar WhatsApp Tipo No Soportado", "type": "main", "index": 0 } ], [ { "node": "Enviar WhatsApp Tipo No Soportado", "type": "main", "index": 0 } ] ] }, "Google Gemini Chat Model": { "ai_languageModel": [ [] ] }, "Structured Output Parser": { "ai_outputParser": [ [] ] }, "Get audio URL": { "main": [ [ { "node": "Download Audio1", "type": "main", "index": 0 } ] ] }, "Download Audio1": { "main": [ [ { "node": "Google Gemini Audio1", "type": "main", "index": 0 } ] ] }, "Google Gemini Audio1": { "main": [ [ { "node": "Format Audio", "type": "main", "index": 0 } ] ] }, "Format Audio": { "main": [ [] ] }, "Get Image URL1": { "main": [ [ { "node": "Download Image", "type": "main", "index": 0 } ] ] }, "Download Image": { "main": [ [ { "node": "Image Explainer", "type": "main", "index": 0 } ] ] }, "Image Explainer": { "main": [ [ { "node": "Enviar WhatsApp Respuesta Texto1", "type": "main", "index": 0 } ] ] }, "Get Video URL1": { "main": [ [ { "node": "Download Video1", "type": "main", "index": 0 } ] ] }, "Download Video1": { "main": [ [ { "node": "Google Gemini Video", "type": "main", "index": 0 } ] ] }, "Google Gemini Video": { "main": [ [ { "node": "Enviar WhatsApp Respuesta Video con Caption", "type": "main", "index": 0 } ] ] }, "Enviar WhatsApp Respuesta Texto1": { "main": [ [] ] }, "Google Gemini Image Model": { "ai_languageModel": [ [ { "node": "Image Explainer", "type": "ai_languageModel", "index": 0 } ] ] } }, "pinData": {}, "meta": { "instanceId": "ccb10ecc3679eb2b535616dd221251b83d055d834fead2ae563f19363cf02302" } } <img width="2982" alt="Image" src="https://github.com/user-attachments/assets/7fb6db2d-4918-49ac-b024-a032b9f61d8f" /> ## Share the output returned by the last node ## Debug info # Debug info ## core - n8nVersion: 1.82.1 - platform: docker (self-hosted) - nodeJsVersion: 20.18.3 - database: sqlite - executionMode: regular - concurrency: -1 - license: enterprise (production) - consumerId: bb248d84-929b-4dc7-bd51-c3f29319ff24 ## storage - success: all - error: all - progress: false - manual: true - binaryMode: memory ## pruning - enabled: true - maxAge: 336 hours - maxCount: 10000 executions ## client - userAgent: mozilla/5.0 (macintosh; intel mac os x 10_15_7) applewebkit/537.36 (khtml, like gecko) chrome/133.0.0.0 safari/537.36 - isTouchDevice: false Generated at: 2025-03-10T23:43:33.870Z ### core - n8nVersion: 1.82.1 - platform: docker (self-hosted) - nodeJsVersion: 20.18.3 - database: sqlite - executionMode: regular - concurrency: -1 - license: enterprise (production) ### storage - success: all - error: all - progress: false - manual: true - binaryMode: memory ### pruning - enabled: true - maxAge: 336 hours - maxCount: 10000 executions ### client - userAgent: mozilla/5.0 (macintosh; intel mac os x 10_15_7) applewebkit/537.36 (khtml, like gecko) chrome/133.0.0.0 safari/537.36 - isTouchDevice: false Generated at: 2025-03-10T23:42:30.844Z}

Unless your errors are different?

solomon · March 14, 2025, 11:46am

Hey @Soho !

Yeah, n8n is the best.

About WhatsApp, there’s a bug being fixed, as Think it mentioned above.

But other than I don’t know about other issues.
I mostly use Evolution API. It’s an unofficial WhatsApp Web API.

Very stable. I think you can connect to WhatsApp Business Cloud too.